Grinding-mill



(NoModeL) M. '0. COGSWELL.

GRINDING MILL.

79W Patented July 26, 1887.

UNITED STATES PATENT OFFICE.

MORTIMER O. GOGSWELL, OF BROOKLYN, NEW YORK.

GRINDING-MILL.

$PECIPICA'I'ION forming part of Letters Patent No. 367,189, dated July 26, 188?. Application filed August 11, 1886. Serial No..2l0,6l7. (No model.)

To all whom it may concern.-

Be it known that I, MORTIMER O. Ooes WELL. of Brooklyn, county of Kings, State of New York, and acitizen of theUnited States, have invented certain new and useful Improvements inGrinding-Mills, of which the following is a full, clear, and exact description, referenee' being had to the accompanying drawings, forming part of this specification.

My present invention relates to improvements upon the grinding-mill for which Letters Patent No. 324,863 were granted to me August 18, 1885; and my invention consists in the combination, in a grinding-mill, with the shaft carrying a balanced disk provided with concentric series of bolt-holes, of similar grinding-plates of uniform Weight, provided with similarly-located bolt-holes registering with the bolt-holes in the disk and formedwith recesses containing soft metal, and screw-bolts for securing said plates to said disk, whereby the said plates are made interchangeable as to both form and weight, and the balance of the grinding-disk preserved.

Figure l is a side elevation of the mill, partly in central longitudinal section, to which my invention relates and containing the'ele mentsof my present invention. Fig. 2 is a face view of one of the revoluble independent-lybalanced disks, showing the independentlybalanced segmental grinding-plates mounted in a set upon the disk in conformity with my invention. Fig. 3 is a rear face view of one of the segmental grinding-plates. Fig. 4 is a cross-section of said plate on line 00 m, Fig. 3; and Fig. 5 is a similar view of the same, showing the plate balanced in conformity with my invention. e

A is the frame on which are mounted the working parts.

B and B are two shafts mounted to revolve in bearings in the frame.

F and F are pulleys on the respective shafts to drive the same. O and Oare two disks secured, respectively, to the inner or opposed, ends of the shafts B B, so that the inner faces of the disks are opposed to one another in parallel planes witha space between them.

D is a curb inclosing the disks,.and is provided wit-h a spout, a, leading to openings central of the curb and disk 0 for the introduction of the material to be ground.

E is a hopper leading to the spout a, through which the material to be ground in the mill may be conveniently fed. An opening, I), in

the curb is provided, through which the ground I independently of the parts thereafter mounted upon them, and before such parts are mountedupon them, as hereinafter described. These disks areseparately balanced on their respective shafts-that is to say, the weight of the metal is distributed equally around the axial center of the shaft, so that in rotation all parts will develop centrifugal force equally. This may be effected by any of the well-known methods employed for such purpose.

cc 0, 81.0., are plates, preferably of hard metal, such aschilled cast-iron, each in the form of a section of a disk and all of the same or equal size or area, so that when assembled, as shown in the drawings, they will constitute a disk or annulus of about the same, or not greater, external'diameter than that of the disks 0 or O. Each of these plates is preferably provided on the grinding-face with radial ribs, as shown, the opposite face being preferably a plane for contact with the face of the disk. These sectional plates 0 are all individually balanced, so that each is of equal weight with every other. This balancing of the plates may be accomplished and secured by mounting one oftheplates upon ashaftupon one sidethereof as, for example, by mounting it flatwise upon a suitable disk or other equivalent holder on the shaft and mounting another plate on the diametricallyopposite side of the shaft on said disk or holder at the same distance from the axial center as the first, and then balancing said plates so that they will develop equal centrifugal force when revolved as thus held I IOO weight and balanced, as in the first instance described. The plates will all be thus individually and interchangeably balanced. 4 To enable this described balancing of the plates to be economically, quickly, and effectively done, I cast or otherwise form a recess-preferably a dovetail recessin the rearward or plane face of each plate, as shown at d, and put into this recess soft metal, such as lead, preferably by melting and running it in, and which may be added to or taken from, as may be required. In this way the plates may all be brought to the same or equal weights, one with another, and thus be balanced on the shaft.

Vith the described balanced disks 0 and O I combine the said grindingplates c, which have been uniformly balanced, as has been de scribed, by such means and in such manner that the plates 0 on the disks C C, respectively, are interchangeable one with another or with others similarly balanced. To accomplish this, I provide the plates with the concentric series of bolt-holes c, the bolt-holes in each plate being coincident in position therein with the boit-holes in every other plate; and I provide the said disks with bolt-holes located therein similarly to and registering with the series of those in the plates, as shown. The screwbolts 0 pass through these bolt-holes thus constituted and arranged when the plates are assembled on the disks, as shown in the drawings, and the plates are thus held to the disks, while at the same time the plates are interchangeable on the disks as to both form and weight and the balance of the disks preserved.

In the operation of these mills the grinding devices are rotated in opposite directions, respectively, at high speed. In a mill of ordinary size, in which the disks are about eighteen inches in diameter, the speed is usually eighteen hundred to two thousand revolutions per minute, the grinding being effected by concussion and attrition of the particles of the material to be ground by being struck and thrown violently back and forth by and between the ribbed faces of the grinding-plates. The necessity of having the oppositely-revolving grinding devices accurately balanced, and this balance maintained, is thus apparent.

The object of my invention is to secure this accurate balance of the revoluble grinding devices, and at the same time to provide for the ready and convenient restoration of this balance when the same may be disturbed and the effectiveness of the mill consequently interfered with by the wear attendant upon the ribbed grindingsurfaces in their action. It is evident that by means of the devices I have described, constructed, and combined, as specified, in case and when the wear upon the ribbed surface of any of the segmental plates 0 causes mill and a new set of similar uniformly-balanced segmental plates may be mounted upon the disk, and the operation of the mill at once proceeded with. The opposed faces of the disks 0 and 0 not being subject to wear in the operation of the mill, their described original balanceis at all times preserved, and the plates are removable from and interchangeable upon the disks, and the balance of the combined disks and plates is at all times maintained.

I am aware that individually-balanced disks arenot new in mills, and I do not claim such disksherein,broadly. Nordolelaim,broadly, herein segmental grinding-plates made of uni form size or area, as such plates have been heretofore made.

"What I claim as my invention, and desire to secure by Letters Patent, iS-- 1. In a grindingmill, the combination,with the shaft Band the balanced disk 0, provided with concentric series of bolt-holes, of the similar grinding-plates of uniform weight, provided with similarly-located bolt-holes regis tering with the bolt'holes in the disk and formed with recesses (1, containing soft metal, and the screwbolts d, for securing said plates to said disks, whereby the said plates are rendered interchangeable as to both form and weight and the balance of the grinding-disk preserved, as set forth.

2. In a grinding-mill, the combination of the shafts B B, the independently-balanced similar disks 0 0', each provided with concentric series of bolt-holes, the similar grinding-plates of uniform weight, provided with similarlylocated bolt-holes registering with the boltholes in the disks and formed with recesses d, containing soft metal, and the screw-bolts d for securing said plates to said disks,whcreby the said plates are rendered interchangeable in both form and weight and capable of being applied to either disk without disturbing the running balance of the mill, as set forth.

MORTIMER O. COGSYVELL.

Witnesses:

A. S. FITCH, A. G. N. VERMILYA. 

